A study led by academics at the universities of Glasgow and Exeter has unveiled that the female guppies swim faster so that they can escape male sexual harassment. In order to avoid unwanted male attention, the female fish change their physiology, so they can swim faster and more efficiently.

In the study, the researchers have exposed female Trinidadian guppies to different level of male harassment for many months. After five months, the researchers noted that that females exposed to higher levels of harassment were able to swim much more efficiently. They were using less energy to swim in comparison to those exposed to lower levels of harassment.

Dr Safi Darden, of the University of Exeter, was of the view that the in the wild, male guppies are seen spending their time courting or pressurizing females to try and mate with them.

Darden said that females find attention by males as unwanted and they try to avoid by rapidly swimming away. “It seems that prolonged increases in high-intensity swimming in females, caused by male harassment, leads to changes in the physiology or swimming mechanics of individual fish, which reduces the energy costs of swimming”, affirmed Darden.

Dr Shaun Killen, of the University of Glasgow, said that sexual coercing of females by males can be seen across the animal kingdom. In the coming time, males of many species will try to have more access through actions like chasing and attacking females in an attempt to do mating.